In existing technologies, a user usually first enters his/her username and password when accessing an online service in order to log into an account of the user that corresponds to the online service for accessing the corresponding online service.
For example, when conducting an online service, such as shopping online, or communicating with others via instant messaging software, or receiving/sending electronic mails via an online mailbox, a user is needed to enter a corresponding username and password to log into a corresponding account for obtaining a corresponding online service.
Moreover, if a user wants to obtain a certain online service but does not have a corresponding account for that online service, the user may register an account corresponding to that online service. During account registration, the user may set up a username and a password for the account to be registered, and use that user name and password for future logins upon successful registration.
However, due to the increasing diversification of online services, a user will need to register one account for every single online service he/she needs, and therefore will need to remember usernames and passwords used by accounts corresponding to each online service. Apparently, along with the diversified development of the online services, a user may easily forget the usernames and the passwords that are used by his/her registered accounts. Once forgotten, the user will have to retrieve the user names and passwords through tedious procedures, thus undoubtedly reducing the efficiency of user account login.
Furthermore, different types of smart mobile devices have been popularly used recently. Other than using a conventional personal computer (PC) for account login, a user may also log into an account using a smart mobile device, such as a smartphone, a tablet, etc. However, because of the miniaturization of smart mobile devices, there exists inconvenience for a user to enter a user name and a password through a smart mobile device, thus further reducing the efficiency of the user account login.